It must be, if you focus on something (first time in your life in this manner), and the resulting shot is in focus, and then you measure the distance and it happened to coincide with a number on the distance scale. It has marks on the mounting plate which I presume do the coupling. Or does "properly rangefinder coupled" simply means you do rangefinder focusing to the best of your ability, take the shot, and the resulting shot is nicely in focus, no matter how perfect is the distance scale reading?
As far as selfish me is concerned, now I know that my ZM 35/2, 50/2 and 85/2 will work great on both cameras. I just still need someone to try a ZM 25/2.8. In my opinion, the 7R seems to be similar in color shift to the M240, which is a step backwards from the M9. So my ZM 25/2.8 should be fine on the 7 and will have a minor shift issue on the 7R. Now how about smearing, that is the question.
v_deakin wrote:
It must be, if you focus on something (first time in your life in this manner), and the resulting shot is in focus, and then you measure the distance and it happened to coincide with a number on the distance scale. It has marks on the mounting plate which I presume do the coupling. Or does "properly rangefinder coupled" simply means you do rangefinder focusing to the best of your ability, take the shot, and the resulting shot is nicely in focus, no matter how perfect is the distance scale reading?
the focus scale has nothing to do with rangefinder coupling (though they should correspond to each other). rangefinder coupling means that a tab on the back of the lens that moves with the focus group of the lens is the correct distance from the mount so that it pushes the interface on a rangefinder camera the correct distance allowing you to focus accurately using the rangefinder patch in the viewfinder of a rangefinder camera.
did you focus it using the rangefinder patch on the camera? if so it's probably correctly coupled. if you post a picture of the back of the lens i can probably tell you which part is the rangefinder coupling. not that it matters if you never use it on a rangefinder – i was just curious if they include that in the conversion (it's a trickier process for non-normal focal length lenses).
Edward, as much as i want the ZM35 to work, I'm not so sure it is okay. Looking at Steve Huff's ZM35 photo Here. The inner two legs of the stool are much sharper than the outer two legs, leading me to believe that there still might be a chance that the lens smears (or there's some very strong field curvature there).
Hopefully Steve posts more photos that we can glean information from, but i think he's just going to drag it out to increase traffic to his site.
"did you focus it using the rangefinder patch on the camera? if so it's probably correctly coupled. if you post a picture of the back of the lens i can probably tell you which part is the rangefinder coupling. not that it matters if you never use it on a rangefinder – i was just curious if they include that in the conversion (it's a trickier process for non-normal focal length lenses).
"
I did focus using the rangefinder patch and will post a shot of the back of the lens, maybe not tonight. It does have about six indents on the brass ring around the bayonet.
ok, i just looked at the huff's b&w zm 21/2.8 + A7 shot on a real non-phone screen and it's got dramatic U shaped field curvature. i don't know if that is present on the m9 but it does not bode well at all for corner performance at any focus distance with that combo (ron already demonstrated that it isn't very good at infinity below f/11).
^ I think you are referring to this photo Here and I agree with your assessment, but it kind of looks more like smearing. To my knowledge, Steve Huff has never given a single piece of equipment a bad review, ever.
Jabberwockt wrote:
^ I think you are referring to this photo Here and I agree with your assessment, but it kind of looks more like smearing. To my knowledge, Steve Huff has never given a single piece of equipment a bad review, ever.
it's curvature. check the lamp post and buildings in the background. you can even see focal "plane" zoom back through the grass. i'm guessing its due to the cover glass based astigmatism.
Jabberwockt wrote:
^ I think you are referring to this photo Here and I agree with your assessment, but it kind of looks more like smearing. To my knowledge, Steve Huff has never given a single piece of equipment a bad review, ever.
He did a really great comparison of the cv 28/2 (or 1.9) vs Summicron 28, years ago which is buried somewhere on the web. He didn't say anything bad about either but he showed the difference, which, of course increased as the aperture was opened.
More recently he has poo-pooed looking at corners as peeping.
@edward: we have no evidence whatever the zm 35/2 is sharp on the edges. I certainly hope it is.
It is so friggin easy to produce decent basic test shots---infinity at 100ft plus with details at least in one corner, but we don't have them yet for the A7r on anything but the summilux 50--strike that- it was not infinity.
It's not just us here who are desperate to see these, but all over the world there are folks asking.
Ron did produce some decent tests with the A7, though I prefer a more distant view.
There is peeping and there is peeping. What most really want to know, can I shoot a landscape shot with the lens?
As we know, many RFs can't do that on any Nex. My skopars 21, 28, and 35 can not do it. They are sharp as hell in the center, but to some degree the edges fall short, even at f/8. By f/16 overall sharpness is starting to suffer.
Brian Smith tweeted me the zm18 "corners are OK", but his sample was unintelligible.
It's not that you can't make fun shoots with soft corners and sharp centers, but when I'm in the backcountry it's not acceptable.
Jabber, Uhoh7, I agree that infinity test shots are very crucial at this time and desperately needed.
As for the ZM 21/2.8, I have never used it, but according to the MTF and my experience with other ZM, it does have field curvature but the b/w sample shot is just incredible. The field curvature cannot be that strong unless the sensor toppings could have exacerbated it as suggested above, but that would be the first time I ever hear that the glass cover can actually curve the plane of sharp focus instead of just blurring it.
PS: the ZM 25/2.8 has a very flat field of focus, so I would know immediately when I see samples how does it perform compared to the M9.
OK, I checked the ZM 35/2 shot on a proper screen (I was looking at them on my ipad this morning), and it does show the same incredible U shaped field curvature, and for this lens that I actually own and use everyday, I know it does not show this kind of curvature on the M9. I think I will stick to my Leica
Jabberwockt wrote:
Edward, as much as i want the ZM35 to work, I'm not so sure it is okay. Looking at Steve Huff's ZM35 photo Here. The inner two legs of the stool are much sharper than the outer two legs, leading me to believe that there still might be a chance that the lens smears (or there's some very strong field curvature there).
Hopefully Steve posts more photos that we can glean information from, but i think he's just going to drag it out to increase traffic to his site.
edwardkaraa wrote:
Jabber, Uhoh7, I agree that infinity test shots are very crucial at this time and desperately needed.
As for the ZM 21/2.8, I have never used it, but according to the MTF and my experience with other ZM, it does have field curvature but the b/w sample shot is just incredible. The field curvature cannot be that strong unless the sensor toppings could have exacerbated it as suggested above, but that would be the first time I ever hear that the glass cover can actually curve the plane of sharp focus instead of just blurring it.
cover glass basically only curves the sagital focus "plane", it doesn't really effect the tangential focus "plane" for reasons that become obvious if you draw a ray diagram. separation of sagital and tangential planes of focus is called astigmatism, so we say that the cover glass is introducing astigmatism. toothwalker has a great explanation of astigmatism in general: http://toothwalker.org/optics/astigmatism.html
sebboh wrote:
cover glass basically only curves the sagital focus "plane", it doesn't really effect the tangential focus "plane" for reasons that become obvious if you draw a ray diagram. separation of sagital and tangential planes of focus is called astigmatism, so we say that the cover glass is introducing astigmatism. toothwalker has a great explanation of astigmatism in general: http://toothwalker.org/optics/astigmatism.html
Thanks for that link
Well, regardless of scientific explanations, the fact is both the ZM 35/2 and 21/2.8 show unnatural and super exaggerated field curvature on the A7. So this option is out as far as I'm concerned. Let's see what the A7R can do.
Well, regardless of scientific explanations, the fact is both the ZM 35/2 and 21/2.8 show unnatural and super exaggerated field curvature on the A7. So this option is out as far as I'm concerned. Let's see what the A7R can do.
sometimes it can be useful, i doubt huff would've been able to get as much of the horse and man in focus at the same time without it.
Well, I'm trying to upload the promised picture of the back of the Hawk'd G21, but I'm required to become an Upload and Sell member and pay a little fee. Is there another way to be a responsible FM denizen?
v_deakin wrote:
Well, I'm trying to upload the promised picture of the back of the Hawk'd G21, but I'm required to become an Upload and Sell member and pay a little fee. Is there another way to be a responsible FM denizen?
free flickr account (or other image uploading site) and simply copy the image url (it'll end in .jpg) into a post.
edwardkaraa wrote:
Well, regardless of scientific explanations, the fact is both the ZM 35/2 and 21/2.8 show unnatural and super exaggerated field curvature on the A7. So this option is out as far as I'm concerned. Let's see what the A7R can do.
If A7/A7R has unsolvable problems on RF WA lenses, then there is no point that I'd consider it over the 6D or 5D for alt lenses. (Size or weight is not my primary concern)
The rare Hawk Contax G to M conversions have a threaded rangefinder cam. The cam is not very visible in the v_deakin photos. It is basically up to the user to calibrate it.
As long as the lens hard infinity stop gives a good infinity focus, then the threaded cam can be turned to give a co-incident rangefinder image on the M camera and then it is lock-tited with a drop.
By the way, Hawk sells a 50mm M helical on ebay for almost $300, that has a better helical and the same threaded rangefinder cam. Remember, the M rangefinder helicals vary by pitch to work with the rangefinder. I have one of these with a Nikon Millennium 50, I am anxious to try out on the full frame Sony...
